We had a backyard rink and a backyard zamboni when I was growing up. I was fortunate enough to have a father who really knew how to make it work. He is a self employed contractor who does a little bit of everything, and takes a lot of pride in his work, as he did with our rink.
However, if you are looking for a good way to keep and make your ice really nice, here iss what we did to build our backyard zamboni, and let me tell you, this backyard zamboni worked like magic. We often had better ice than many of the indoor rinks that I skated on.
He built a 4x1.5 foot box lines with rubber roof and put a hole through the middle of it. Underneath the box, we placed a deflated bike tire and used a cooler which fit inside the box. We then attached a rope to pull it by and filled the cooler with HOT WATER. Open the release valve on the cooler and zamboni how you please. It was an amazing contraption and is definitely worth it. If you want great ice, make your own zamboni!
This backyard zamboni works so much better than flooding it with a hose. TRUST ME!!!